Chile has summoned home its ambassador to Peru for consultations, amid resurgent tensions between the neighbours over maritime boundaries.
At stake in the long-running spat are rich fishing waters
The recall comes a day after Peru asked the International Court of Justice at The Hague to consider the dispute.
Now the Chilean foreign minister says he wants to consult their envoy to Lima to "ensure a decent legal defence".
At stake is a large area of sea which is rich in fish, representing an important source of commercial income.
But this is also just the latest spat in a history of disputes between the two dating back to the 19th Century.
Peru, which asserts that at present there is no legally defined sea border, on Wednesday filed a suit with the UN's highest judicial organ asking it to rule on the matter.
The court could take five or six years to decide the case.
Peru suggests the line should run south-westerly from the coast, following the direction of the land border.
But Chile argues that Peru is overlooking bilateral treaties agreed in 1952 and 1954 which settled the maritime border - which it says runs due west from the coast.
The Pacific Ocean area claimed by Peru, said Chile on Wednesday, is "unquestionably under Chilean sovereignty and jurisdiction", reported the Associated Press news agency.
And on Thursday it urgently recalled its envoy, Christian Barros, for what Foreign Minister Alejandro Foxley called "an extended discussion".
He said such discussions would help "ensure a decent legal defence of Chile and also allow us to maintain normal relations between our neighbour countries".
There is a history of disputes over land and sea borders in this region, say correspondents - not only between Peru and Chile, but between Bolivia and Chile.
The disputes mainly date back to the 1879-1883 War of the Pacific, in which Chile took mineral-rich land from both - in the case of Bolivia, it seized its only outlet to the sea.